Three cameras each loaded with 400 ft of film were mounted on wind vanes and set up in the triangular configuration A.B.C. Each camera was accompanied by a microphone and tape recorder which recorder simultaneously throughout the shooting. Only one camera was running at any one time. The decision to switch from one camera to another was governed by the wind velocity at points A. B. and C. The wind velocity was continuously assessed by three independent anemometers and this information was monitored electronically.
A camera was switched on by the electronics when its corresponding anemometer indicated a wind velocity greater than the velocity indicated at the other two points. It remained on until either a higher wind velocity was reached elsewhere or its own velocity fell below the set limit zero. When all three anemometers indicated a reading lower then zero no film was shot. This procedure continued until all three cameras ran out of film. The three rolls of film were edited, complete with corresponding sections of synch sound, into one roll which has the same temporal order as that observed whilst the film was being shot. – C.W.